Prions are killed by
**Core Concept**
Prions are infectious proteins that cause fatal neurodegenerative diseases, such as Creutzfeldt-Jakob disease in humans and BSE (Mad Cow Disease) in cattle. They are unique in that they do not contain nucleic acids, making them resistant to conventional sterilization methods.
**Why the Correct Answer is Right**
Prions are notoriously resistant to various methods of inactivation, including heat, ultraviolet light, and chemical disinfectants. However, they can be effectively inactivated by autoclaving at high temperatures (typically 134°C for 18 minutes) and subsequent exposure to 2M NaOH, which denatures the protein structure and renders it non-infectious. This process is crucial in preventing the spread of prion diseases through contaminated surgical instruments or tissues.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is likely incorrect because prions are not susceptible to inactivation by simple heat sterilization, which may not reach the high temperatures required to denature the protein.
* **Option B:** This option is incorrect as prions are not effectively inactivated by standard chemical disinfectants, which may not penetrate the protein structure to cause denaturation.
* **Option C:** This option is incorrect as prions are not killed by ultraviolet light, which may not have sufficient energy to cause the protein structure to denature.
**Clinical Pearl / High-Yield Fact**
Prions are highly resistant to inactivation, and their unique protein structure makes them challenging to eliminate. It is essential to follow strict protocols for sterilization and decontamination when handling tissues or instruments that may be contaminated with prions.
**Correct Answer:** D. Autoclaving and 2M NaOH.